To claim "100%" of pitchers who threw with the "inverted W" had career-ending injuries, one would need to produce video or photographic evidence of every major league pitcher who had ever thrown that way, along with substantiated newspaper accounts, or preferably, medical records, for every one of those pitchers.

Without that, it's unsubstantiated hyperbole.

You know what would be easier than that? Giving an example of one guy who didn't.